Conditional knockout mice lacking K(ATP) channel subunits

描述（由申请人提供）：KATP通道是许多不同类型细胞和组织功能的组成部分。然而，尽管它们在近25年前首次被描述，但这些通道的生理和病理生理作用直到现在才出现在大多数组织中。电生理学和药理学方法已经允许很好地理解KATP通道的作用。KATP通道（Kir6.1、Kir6.2、SUR 1、SUR 2A和/或SUR 2B亚基）的分子鉴定进一步推进了我们关于这些通道的分布和功能的知识。要检查的最重要的假设是，生理和病理生理事件受到存在于多种组织中的KATP通道的活性的影响，并且不同组织类型中的通道活性之间的同步相互作用决定了生理或病理生理结果的性质。传统的药理学方法不能用于在复杂的生物学环境中检验该假设，因为这些化合物缺乏对存在于不同组织类型中的不同类别的KATP通道所需的特异性。已经为每个KATP通道亚基开发了常规敲除小鼠模型，并且这些动物模型的可用性显著增加了我们对KATP通道在体内环境中的功能的了解。然而，由于在所有体细胞中表达被消除，因此当定义KATP通道亚基在复杂生物环境（例如缺血/再灌注）中的作用时，使用这些动物提供了挑战。为了研究存在于多种组织中的KATP通道的相互作用以及它们在不同组织类型中的同步相互作用，需要新的工具，其中KATP通道仅在特定组织、细胞类型或亚细胞区室中被消除。因此，本建议的目的是产生四种KATP通道亚基的条件性敲除的小鼠模型。鉴于KATP通道的丰富多样性（就其组织分布和分子组成而言），迫切需要产生缺乏每个KATP通道亚基的条件性敲除小鼠。这些动物模型的开发将产生广泛的影响，不仅对我们自己的研究，而且对整个领域产生广泛的影响，因为作为这些研究的一部分产生的这些动物将允许在不同领域（心脏病学，内分泌学，神经学等）工作的研究人员解开KATP通道在健康和疾病中的组织特异性功能。公共卫生相关性：ATP敏感性钾通道是一类独特的钾通道，它参与细胞内能量代谢，调节细胞的活性和兴奋性，对多种细胞的功能具有重要作用，有助于维持血糖水平，调节血流，参与神经递质的分泌，保护细胞免受缺血性损伤。在生理和病理生理背景下研究KATP通道出现了新的挑战，这些挑战无法使用现有的工具（即使是可用的常规敲除小鼠）解决，这是我们提出产生新的遗传改变的小鼠模型的基本原理，其中KATP通道亚基可以在某些组织类型中特异性缺失。这些小鼠将与科学界广泛分享，无疑将在许多研究领域（除了我们自己的研究之外）的KATP通道研究中取得重大突破，这将对生物医学，行为和临床研究领域产生重大影响。

DESCRIPTION (provided by applicant): KATP channels are integral to the functions of many different types of cells and tissues. However, even though they were first described almost 25 years ago, the physiological and pathophysiological roles of these channels are only now emerging for most tissues. Electrophysiological and pharmacological methods have allowed for a good understanding of the roles of KATP channels. The molecular identification of KATP channels (Kir6.1, Kir6.2, SUR1, SUR2A and/or SUR2B subunits) has further advanced our knowledge regarding the distribution and function of these channels. The overriding hypothesis to be examined is that physiological and pathophysiological events are subject to the activity of KATP channels that are present in multiple tissues and that synchronous interaction between channel activities in diverse tissue types determines the nature of the physiological or pathophysiological outcome. Conventional pharmacological methods cannot be used to examine this hypothesis in a complex biological setting since these compounds lack required specificity for different classes of KATP channels present in diverse tissue types. Conventional knockout mouse models have been developed for each of the KATP channel subunits and the availability of these animal models has added significantly to our knowledge of the functions of KATP channels in the in-vivo setting. However, since the expression is eliminated in all somatic cells the use of these animals provides challenges when defining the roles of KATP channel subunits in complex biological settings (such as ischemia/reperfusion). To examine the interplay of KATP channels present in multiple tissues and their synchronous interaction in diverse tissue types, new tools are needed in which KATP channels are eliminated only in specific tissues, cell types or subcellular compartments. The purpose of this proposal is therefore to generate four mouse models of conditional knockouts of each of the KATP channel subunits. Given the rich diversity of KATP channels (both in terms to their tissue distribution and molecular composition), a dire need exists to generate conditional knockout mice devoid of each of the KATP channel subunits. The development of these animal models will have a wide ranging impact, not only on our own research, but also on the field in general since these animals generated as part of these studies will allow investigators working in diverse areas (cardiology, endocrinology, neurology, etc) to unravel the tissue specific functions of KATP channel in health and disease. PUBLIC HEALTH RELEVANCE: ATP-sensitive K+ channels are unique in that they transduce intracellular energy metabolism to cellular activity and excitability and they have very important roles on the functions of many different cell types and they help to maintain blood glucose levels, regulate blood flow, participate in the secretion of neurotransmitters and protect against ischemic insults. New challenges have arisen in the study of KATP channel in physiological and pathophysiological context that cannot be addressed using existing tools (even with the available conventional knockout mice), which is the rationale for our proposal to generate new genetically altered mouse models in which KATP channel subunits can be deleted specifically in certain tissue types. These mice, which will be widely shared with the scientific community, will undoubtedly lead to significant breakthroughs in the study of KATP channels in many study areas (in addition to our own research) and this will have a major impact on the fields of biomedical, behavioral and clinical research.